PAXgene Tissue FIX Container (50 ml)

For collection, fixation and stabilization of multiple small or a single large tissue sample

Formalin-free preservation of morphology and biomolecules

Improved molecular results from fixed tissues

Tissue can be stored and archived for later processing

RNA, miRNA, DNA, and/or proteins from one sample

The PAXgene Tissue FIX Container is intended for the collection, fixation and stabilization of tissue specimens. The container is part of the PAXgene Tissue System and must be used with the PAXgene Tissue STABILIZER Concentrate. The PAXgene Tissue System additionally includes the PAXgene RNA/miRNA Kit for isolation of total RNA, including miRNA, and PAXgene Tissue DNA Kit for DNA. Supplementary protocols are available for other applications, including purification of proteins.

Yield of high-quality, high molecular weight DNA from 12 different PAXgene Tissue-fixed (PF) tissue types, processed on the QIAcube.

Twelve different PAXgene Tissue-fixed (PF) rat tissue types, including fibrous or fatty, DNA-rich and DNA-poor tissues, processed with the PAXgene Tissue DNA Kit on the QIAcube in one single run. DNA yield per 10 mg tissue.

Twelve different PAXgene Tissue-fixed (PF) rat tissue types, including fibrous or fatty, DNA-rich and DNA-poor tissue, processed with the PAXgene Tissue DNA Kit on the QIAcube in a single run. Ratio of absorbance at 260 and 280 nm.

Ratio of absorbance at 260 and 280 nm from 3 sections (thickness 10 µm) each of 8 different PAXgene Tissue-fixed, paraffin-embedded (PFPE) rat tissue types processed in triplicate with the PAXgene Tissue DNA Kit on the QIAcube or manually.

Human palatine tonsil tissue was fixed in PAXgene Tissue FIX or with neutral-buffered formalin and embedded in paraffin. Primary antibodies to the indicated antigens were linked to a streptavidin-peroxidase conjugate by a biotinylated secondary antibody (LSAB method). Sectiosn were counterstained with hematoxylin. PFPE: PAXgene Tissue-fixed, paraffin-embedded. FFPE: formalin-fixed, paraffin-embedded.

H&E staining with the PAXgene Tissue System gives results comparable to formalin-fixed tissue.

Human tissue samples were divided into 2 sub-samples. One sub-sample was fixed with PAXgene Tissue FIX and the other was fixed with neutral-buffered formalin. The fixed tissues were embedded in paraffin, sectioned and stained with hematoxylin and eosin. PFPE: PAXgene Tissue-fixed, paraffin-embedded. FFPE: formalin-fixed, paraffin-embedded.

Enhanced storage
When tissues are stored in PAXgene Tissue STABILIZER, nucleic acids, proteins and morphology of the tissue sample are stable for up to 7 days at room temperature (15–25°C) or 4 weeks at 2–8°C, depending on the type of tissue. Tissue samples can be stored in PAXgene Tissue STABILIZER for longer periods at –20°C (–15°C to –30°C) or –80°C (–65°C to –90°C) without negative effects on the morphology of the tissue or the integrity of the biomolecules.

Note: Specifications for fixation and storage conditions in PAXgene Tissue STABILIZER were determined using animal tissues. Storage at 2–8°C for more than 4 weeks must be validated for each tissue type.

Note: For storage at –20°C (–15°C to –30°C) or –80°C (–65°C to –90°C), use cryogenic vials with screw caps filled with PAXgene Tissue STABILIZER. For safety reasons, note that the PAXgene Tissue STABILIZER contains 70% ethanol by volume.

The methods for tissue fixation currently used in traditional histology are of limited use for molecular analysis. Fixatives that contain formaldehyde crosslink biomolecules and modify nucleic acids and proteins. Such crosslinks lead to nucleic acid degradation during tissue fixation, storage and processing. Since they cannot be removed completely, the resulting chemical modifications can lead to limitations in downstream applications, such as RT-PCR, qPCR and next-generation sequencing. The PAXgene Tissue FIX Container enables formalin-free fixation of tissue specimens. In combination with the PAXgene Tissue STABILIZER Concentrate, which enables formalin-free stabilization, tissue morphology and biomolecule integrity are preserved by avoiding destructive crosslinking and degradation found in formalin-fixed tissues (see The PAXgene Tissue FIX Container (50 ml) and PAXgene Tissue STABILIZER workflow).

Procedure

PAXgene Tissue FIX Containers are single-chamber containers prefilled with 50 ml of PAXgene Tissue FIX. PAXgene Tissue FIX Containers can accommodate 4 standard tissue cassettes (not provided), which can hold tissue samples with a maximum size of 4 x 15 x 15 mm. PAXgene Tissue FIX Containers also offer the possibility for direct fixation of larger tissue samples with a maximum size of 20 x 20 x 20 mm. PAXgene Tissue FIX rapidly penetrates and fixes the tissue. After fixation for 2 to 72 hours, depending on tissue size, PAXgene Tissue FIX is removed and replaced by PAXgene Tissue STABILIZER within the same container. Stabilized samples can be embedded in paraffin for histological studies, and nucleic acids and proteins can be isolated from the stabilized samples before or after embedding in paraffin.